# US 11,443,222 B2 · Cross-resonance fan-out for efficiency and hardware reduction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,443,222 B2 - Document ID: US11443222B2 - Status: Granted - Kind: B2 - Application number: 16/666,553 - Filed: 2019-10-29 - Published: 2020-02-27 - Granted: 2022-09-13 - Earliest claimed: 2017-09-29 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Jerry M. Chow; Antonio D. Corcoles-Gonzalez; Jay M. Gambetta - Web page: https://patentgrep.com/patent/US11443222B2 ## CPC - H03K 3/38: by the use, as active elements, of superconductive devices - G06F 1/06: Clock generators producing several clock signals {(G06F1/08 - G06F1/14 take precedence)} - G06F 1/08: Clock generators with changeable or programmable clock frequency - G06F 1/10: Distribution of clock signals {, e.g. skew} - G06N 10/40: Physical realisations or architectures of quantum processors or components for manipulating qubits, e.g. qubit coupling or qubit control - H01P 1/213: combining or separating two or more different frequencies (H01P1/215 takes precedence) - H03D 7/00: Transference of modulation from one carrier to another, e.g. frequency-changing (H03D9/00, H03D11/00 take precedence; dielectric amplifiers, magnetic amplifiers, parametric amplifiers used as a frequency-changers H03F) - H03K 3/02: Generators characterised by the type of circuit or by the means used for producing pulses (H03K3/64 - H03K3/84 take precedence) - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G06N: COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS - H01P: WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE (operating at optical frequencies G02B) - H03D: DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER (masers, lasers H01S; circuits capable of acting both as modulator and demodulator H03C; details applicable to both modulators and frequency-changers H03C; demodulating pulses H03K9/00; transforming types of pulse modulation H03K11/00; coding, decoding or code conversion, in general H03M; repeater stations H04B7/14; demodulators adapted for AC systems of digital information transmission H04L27/00; synchronous demodulators adapted for colour television H04N9/66) ## Abstract A signal generating system is provided. The signal generating system provides a microwave signal to a plurality of qubits. The signal generating system includes a generator, an oscillator, a mixer, and a splitter. The oscillator generates an oscillator signal including a constant frequency. The generator generates a generator signal including an initial frequency. The mixer is electrically coupled to the generator and the oscillator. The mixer combines the generator and oscillator signals to produce the microwave signal. The splitter is electrically coupled to the mixer. The splitter fans-out the microwave signal to a plurality of physical lines. Each of the plurality of physical lines is electrically connected to a corresponding one of the plurality of qubits. ## Claims ### Claim 1 A system comprising: an oscillator circuit comprising an oscillator coupled to a first splitter, the oscillator being configured to generate an oscillator signal comprising a constant frequency, the first splitter comprising a plurality of terminals; a plurality of mixers, the plurality of terminals of the first splitter respectively terminating at the plurality of mixers, each mixer of the plurality of mixers being electrically coupled to a generator; and a plurality of splitters, each splitter of the plurality of splitters being connected to a corresponding one of the plurality of mixers respectively, the plurality of splitters being configured to fan-out a microwave signal, respective outputs of each splitter being connected to a plurality of physical lines respectively, wherein each line of the plurality of physical lines for one splitter is not merged with the plurality of lines of another splitter of the plurality of splitters, the respective outputs of the plurality of splitters being connected to a respective qubit of a plurality of qubits. ### Claim 2 (depends on 1) The system of claim 1, wherein the plurality of splitters each comprise a switch. ### Claim 3 (depends on 1) The system of claim 1, wherein: the generator is configured to generate a generator signal comprising an initial frequency; and each of the plurality of mixers is configured to combine the generator and oscillator signals to produce the microwave signal. ### Claim 4 (depends on 3) The system of claim 3, wherein the microwave signal comprises a combined frequency based on a summation of the initial and constant frequencies within one mixer of the plurality of mixers. ### Claim 5 (depends on 3) The system of claim 3, wherein the generator comprises an arbitrary waveform generator that provides the generator signal to one mixer of the plurality of mixers. ### Claim 6 (depends on 1) The system of claim 1, wherein each of the plurality of splitters is configured to distribute the microwave signal to the plurality of physical lines in time. ### Claim 7 (depends on 1) The system of claim 1, wherein the plurality of splitters are configured to distribute the microwave signal to the plurality of physical lines according to a state of switches coupled to the plurality of physical lines. ### Claim 8 A method of configuring a system, the method comprising: configuring an oscillator circuit comprising an oscillator coupled to a first splitter, the oscillator being configured to generate an oscillator signal comprising a constant frequency, the first splitter comprising a plurality of outputs; providing a plurality of mixers, the plurality of terminals of the first splitter respectively terminating at the plurality of mixers, each mixer of the plurality of mixers being coupled to a generator; and providing a plurality of splitters, each splitter of the plurality of splitters being connected to a corresponding one of the plurality mixers respectively, the plurality of splitters being configured to fan-out a microwave signal, respective outputs of each splitter being connected to a plurality of physical lines respectively, wherein each line of the plurality of physical lines for one splitter is not merged with the plurality of lines of another splitter of the plurality of splitters, the respective outputs of the plurality of splitters being connected to a respective qubit of a plurality of qubits. ### Claim 9 (depends on 8) The method of claim 8, wherein the plurality of splitters each comprise a switch. ### Claim 10 (depends on 8) The method of claim 8, wherein: the generator is configured to generate a generator signal comprising an initial frequency; and each of the plurality of mixers is configured to combine the generator and oscillator signals to produce the microwave signal. ### Claim 11 (depends on 10) The method of claim 10, wherein the microwave signal comprises a combined frequency based on a summation of the initial and constant frequencies within one mixer of the plurality of mixers. ### Claim 12 (depends on 10) The method of claim 10, wherein the generator comprises an arbitrary waveform generator that provides the generator signal to one mixer of the plurality of mixers. ### Claim 13 (depends on 10) The method of claim 10, wherein the generator signal is defined by a voltage versus time of an arbitrary shape. ### Claim 14 (depends on 8) The method of claim 8, wherein each of the plurality of the splitters is configured to distribute the microwave signal to the plurality of physical lines in time. ### Claim 15 (depends on 8) The method of claim 8, wherein the plurality of splitters are configured to distribute the microwave signal to the plurality of physical lines according to a state of individual switches coupled to the plurality of physical lines.